Stuff it into a styrofoam cup with cotton and aluminum wrapped around it and put heaps of salt on the ice cube
You could keep it in a freezer.
put it in the freezer ;)
probably if you keep it in the freezer
The ice cube remains in its shape in the freezer because the temperature inside the freezer is below the ice cube's melting point, preventing it from melting or changing shape. As long as the temperature stays below freezing, the ice cube will remain solid.
Forever if you leave them in the freezer! But it melts in hours.
Put salt on it.
Obviously putting it in the freezer will keep it from melting. Other good insulators are: - Styrofoam - Bubble wrap - Copper
a freezer outside (only if it is below 0)
To keep an ice cube from melting, you can wrap it in a towel or place it in an insulated container. Keeping it away from direct sunlight or heat sources will also help slow down the melting process. Additionally, storing it in a freezer or a cooler with ice packs can help maintain its temperature.
You can prevent an ice cube from melting quickly by keeping it in a well-insulated container, placing it in a cooler with ice packs or dry ice, or storing it in a freezer. Limiting its exposure to warmer temperatures and minimizing air circulation around it can also help slow down the melting process.
The hot atmosphere
Well, first thought would be keep in in the freezer. Covering the ice cube with an insulating material would help, sawdust or woodchips is what they used to use many year ago.